Back Structure for a Chair

ABSTRACT

A rack structure for a chair comprises a chair back member comprised of a frame and a mounting support, wherein the frame includes a support cushion disposed on the front side thereof for supporting a user&#39;s waist correspondingly, and includes two first connecting tabs fixed on the back sides of the top ends of two sides thereof individually, and includes two second connecting tabs formed on and extending from two sides thereof respectively; the mounting support is fixed onto a base and extends upwardly therefrom, and includes two coupling segments and two connecting projections arranged on the top ends and the intermediate sections of two sides thereof respectively, and between each coupling segment and each connecting projection is couplingly attached a resilient member, such that the first and second connecting tabs of the frame are connected with the coupling segments and the connecting projections of the mounting support individually.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a rack structure, and more particularly to a rack structure for a chair that may maintain the user's correct sitting posture by swing the frame thereof.

2. Description of the Prior Arts

For the comfortness reason, most chairs are equipped with a back rack, therefore the rack structure will be the requirement for a comfortable chair.

A conventional rack structure includes a frame comprised of a back plate (the back plate includes soft materials, such as foam material, filled therein) for providing the comfortness as a user sits on the chair and lay against its back. However, such a conventional chair can not make the user correct his sitting posture if sitting on the chair in an incorrect manner, causing a fatigue.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide a rack structure for a chair that may maintain user's correct sitting posture by swing the frame thereof.

In accordance with one aspect of the present invention, there is provided a rack structure for a chair including a chair back member comprised of a frame and a mounting support, wherein

the frame includes a support cushion disposed on the front side thereof for supporting a user's waist correspondingly, and includes two first connecting tabs fixed on the back sides of the top ends of two sides thereof individually, and includes two second connecting tabs formed on and extending from two sides thereof respectively;

the mounting support is fixed onto a base and extends upwardly therefrom, and includes two coupling segments and two connecting projections arranged on the top ends and the intermediate sections of two sides thereof respectively, and between each coupling segment and each connecting projection is couplingly attached a resilient member, such that the first and second connecting tabs of the frame are connected with the coupling segments and the connecting projections of the mounting support individually, hence the frame may be assembled onto the chair by way of the mounting support.

In operation, the frame may be used to support the user comfortably, yet as the user lay on and against the support cushion in an incorrect posture, because the support cushion is pressed by the user and is located beneath the second connecting tab, and the resilient member is attached between the coupling segment and the connecting projection, the user presses the bottom of the frame to swing rearward and then the top end of the frame is urged to pull the resilient members to become bent frontward so as to support and conform the shape of user's back for recovering correct lying postures. On the contrary, as the user lay and biases against the upper side of the frame by his upper back, the bottom of the frame may swing frontward by using the resilient members so that the support cushion may move frontward to support the user, obtaining the comfortness with his changing postures.

To accommodate different users, on each of two sides of the frame is provided with a continuous arcuate groove, and on each of two ends of the support cushion is disposed an arcuate protrusion in response to the arcuate groove for being fixed into the arcuate groove by means of an elongated press member, such that the support cushion may be adjusted upward and downward relative to the frame, thus maintaining the correct sitting posture.

Furthermore, the support cushion includes foam materials filled therein for increasing comfortness.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side plan diagram illustrating the assembly of a rack structure for a chair according to the present invention;

FIG. 2 is a perspective diagram illustrating the exploded components of the rack structure for the chair according to the present invention;

FIG. 3 is a perspective diagram illustrating the assembly of the rack structure for the chair according to the present invention;

FIG. 4 is a side plan diagram illustrating the operational status of the rack structure for the chair according to the present invention;

FIG. 5 is another side plan diagram illustrating the operational status of the rack structure for the chair according to the present invention;

FIG. 6 is a side plan diagram illustrating the assembly of a support cushion of the rack structure for the chair according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 3-5, a rack structure for a chair in accordance with the present invention includes a chair back member 10 comprised of a frame 1 and a mounting support 2 (as shown in FIGS. 1 and 2), wherein

the frame 1 includes a support cushion 3 disposed on the front side thereof for supporting a user's waist correspondingly, and includes two first connecting tabs 11 fixed on the back sides of the top ends of two sides thereof individually, and includes two second connecting tabs 12 formed on and extending from two sides thereof respectively;

the mounting support 2 is fixed onto a base 4 and extends upwardly therefrom, and includes two coupling segments 21 and two connecting projections 22 arranged on the top ends and the intermediate sections of two sides thereof respectively, and between each coupling segment 21 and each connecting projection 22 is couplingly attached a resilient member 23, such that the first and second connecting tabs 11, 12 of the frame 1 are connected with the coupling segments 21 and the connecting projections 22 of the mounting support 2 individually (as illustrated in FIG. 3), hence the frame 1 may be assembled onto the chair by way of the mounting support 2.

In operation, the frame 1 may be used to support the user comfortably, yet as the user lay on and against the support cushion 3 in an incorrect posture, because the support cushion 3 is pressed by him and is located beneath the second connecting tab 12, and the resilient member 23 is attached between the coupling segment 21 and the connecting projection 22, the user presses the bottom of the frame 1 to swing rearward and then the top end of the frame 1 is urged to pull the resilient members 23 to become bent frontward (as shown in FIG. 4) so as to support and conform the shape of user's back for recovering correct lying posture. On the contrary, as the user lay and biases against the upper side of the frame 1 by his upper back, the bottom of the frame 1 may swing frontward (as illustrated in FIG. 5) by using the resilient members 23 so that the support cushion 3 may move frontward to support him, obtaining the comfortness with the changing postures.

To accommodate different users, on each of two sides of the frame 1 is provided with a continuous arcuate groove 13 (as shown in FIG. 6), and on each of two ends of the support cushion 3 is disposed an arcuate protrusion 31 in response to the arcuate groove 13 for being fixed into the arcuate groove 13 by means of an elongated press member 32, such that the support cushion 3 may be adjusted upward and downward relative to the frame 1, thus maintaining the correct sitting posture.

Furthermore, the support cushion 3 includes foam materials filled therein for increasing comfortness.

The invention is not limited to the above embodiment but various modifications thereof may be made. It will be understood by those skilled in the art that various changes in form and detail may be made without departing from the scope and spirit of the present invention. 

1. A rack structure for a chair including: a chair back member comprised of a frame and a mounting support, wherein said frame includes a support cushion disposed on the front side thereof for supporting a user's waist correspondingly, and includes two first connecting tabs fixed on the back sides of the top ends of two sides thereof individually, and includes two second connecting tabs formed on and extending from two sides thereof respectively; said mounting support is fixed onto a base and extends upwardly therefrom, and includes two coupling segments and two connecting projections arranged on the top ends and the intermediate sections of two sides thereof respectively, and between each coupling segment and each connecting projection is couplingly attached a resilient member, such that said first and second connecting tabs of said frame are connected with said coupling segments and said connecting projections of said mounting support individually.
 2. The rack structure for the chair as claimed in claim 1, wherein said support cushion includes foam materials filled therein for increasing comfortness. 